Photographic shutter.



A. WOLLENSAK.

PHOTOGRAPHIC SHUTTER. APPLICATION FILED APR.21, 1915.*

1,170,207. Y Patented Feb. 1, 1916.

o 1920 24 29 23 26 25 Wnnns: 21 31 30 Illvemag 4MM h/.9 @www y 7M g LUNITED STATES reTNToFFGE.,

ANDREW WOLLENSAK, OE ROCHESTER, NEW YoRK;Ass1GNOR 'ro WoLEENsAK OPTICAL COMPANY, OE ROCHESTER, NEW YORK, A CORPORATION or NEW YORK.

' PHOTOGRAPHIC sinirr'iiER.v

To alli/whom t may concern.' f v Beit known that I, ANDREwgWOLLENsAK,

A a citizen'o-f the United States, and resident a specication.

IAD

of Rochester, in the county lofMonroe and' State of ANew York, have invented certain new and useful Improvements in Photographic Shutters, of which the following is This inventionl r USU- `ment imparted to theretarder by the actuating-mechanism of the shutter;

In the shorter eXposures,ihowever, the inertia of the mechanism of the retarder plays a large, f and perhaps the chief part, in the retardingV function, ywhile, the stroke or movementV which isimparted to the retarder is` so short that in the case ofa pneumatic retarder the slight increase in airpressureresulting fromr it has comparatively little/effect. Under these conditions any slight distortion of the parts of the mechanism, or any increase in play or 'lost motion due towear, has a pro iiounced effect on the timing of the mechaiiism, and suoli distortion and wear are likely? tooccur in consequence of the fact that the coperative engagement between the actuat-E ing-mechanism and the retarder is usually in the' nature of `a blow, which is most accentuatedinthe case of the shorter ex-V posures.

In accordance 'with the present invention A the disadvantages above set f forth are;

avoided by a construction and organization of thel parts suoli that the cooperative en` gagement between the actuating-mechanism and the retarding-mechanism is comparatively long,y even in the production 'of'the shorter exposures, the necessary variations in the retardingl effect being secured by an arrangement through Whichfthe actuatingmechanism operates on the retarding-mech-- anism with a mechanicaly advantage which Specication of Letters Patent. i y

elates to photographic" shutters'of the type in which exposures of measured duration are obtained auto-mati-` Patented Feb. 1,1916.

ApplicatienniedAprii27,1915@seria1No.24,a67. r

increases rapidly toward the end of the operative'movemelit of the parts.y In` this man ner: it' is possible to secure a less sudden and more prolongedengageinent, for thesliorter exposures, and thus to largely eliminate the hammering action characteristic `of the usual constructions,and also to'reduce the proportionate effect of inertia, since the retardingmechanism isl thrown into movement less suddenly, the length of the vcooperative movement ofthe parts being greater in all cases, 'except that of the longest exposures;

` In the preferred `form of the invention the change in `mechanical advantage just referred to is secured 'by the use of coperating levers so formed and arranged as to act upon eachother with varying eective leverarms.`- i

Inthe accompanying drawings z-Figures l, 2 and 3 are'frOnt-elevations of a yshutter embodying the present invention,` with the frontfcover-plate andoertaiii parts of the fmechanism removed, andshowing the mech-,

, anism in different positions; and Fig. dis a bottom-view of the shutter, with a part of the casing broken awayto show the mechanism.

The illustrated shutter, in its general organiz'ation and mode of operationeis substantially` the same yas that disclosed in Letters PatentV -of i th-e United States No. 1,085,762, grantedl Aug. 13, :1912, to the `present inventor, and/only soinuch of the mechanism' of the shutter is illustrated as is necessary for an understanding of the i1nprovement disclosed.

^ The illustrated shutter has the usual `oscil-` lating -.shutterfblades 'rconnected, in any'ordinary or suitable manner, with a blade-ring f 6 'which has a forked pijojectionengaged by a lug V7 depending from an'eXposurelever 8.

The exposure-lever 8 is mounted on a pivot' 9, and is moved'iny one direction by a spring 10.'rk It is moved in the opposite direction by4 ,means of a master-'lever 11', whichis mounted gona pivot 12 and moved in one direction yby a spring 13. Abeveled lug r'14, near the lower end kofthe master-lever, cooperates y ywith a beveled lug 15 yon the'eXposure-lever, riso asto rockthe latter Afrom the position of Fig. l, in which the shutter-blades are closed, to the position of Fig. 2, in which the blades are, open, and then to release the exposure-lever andy permit it to close the blades again, after the master-lever has its i movedfjastbeyend the position siiwnfin Fig. 3.

`The master-lever is actuated by coperation Ywith an. actuating-lever 16, which may be moved by a finger-button 17, or inany` other convenient or usual manner. The

yparts so far described are all substantially the same in construction andoperation as i the shutterof the said patent.M e e e y., Y, The retarder is illustrated as `comprising `anv air-cylinder 18, y in which a piston 19 performed bythe retarder-piston;Aspring i f 33, associated Vwith theretarder-lever, tends" to swing -it in a direction to pull `the ypiston outwardly, and to pressy the lug 21against f the controller-ring. ,y v 5 :i i

Themaster-lever is operatively connected with the retarder-lever by an intermediate v i termediate leverj swings toward the position lever 23, whichisfmounted on a pivot 2,4'and controlled by a spring 27,. The intermediate I lever has abeveled lug 25 `which ycooperates with a-lu'g 26 on the master-leven Thelug 26 rides freely over the lug- 25 s when the master-lever is swung in a clockwise direction, butupon its yreturn-stroke, funderpthe influence of thejspring 13, the square faces ofthe lugs are engaged, and the intermediate leverristherefore rocked in ak clockwise di-k rection until, by reason ofthis'movement, the end of the lug 25 isdrawnKA clear of the lug 26, whereupon the intermediate lever is -re-y turnedto itsjnormal'position bythe spring" 27."y Thislpo'sitionis'determined by afstop` lug`28 projecting from the lever--231intofa slot in the base-plate 29 ofthe mechanism. 'Y

The intermediate lever and the,l retarder-r lever coperate through armsv 8O and 31,fre-

spectively. Inthe normaly Vposition kof the parts, when the shutter is set for the longest,

exposure, these arms liel substantially paralfA lel with eachother, asshown in Fig. 1." In the exposure-movement, however,- as the in-` of Figv 8, which represents its final operative' position, the yangle between the Larms 3O1and 31 changes in sucha manner. that the inter-` mediate lever has a mechanicalfadvantage rover the retarder-lever whichv increasesrap- `idly toward the. end of the movement, `be-=- coming, in fact, infinite Vat 'thecompletion of the operative movement. v Owing to this",`

vment, also permits, and in lfact -requires',fa formation-off the controller `such as tosecure same arrangement, whenthe etardersset f fora "shorter exposure the intermediate'lever leverinthe initial position of the parts, so that the intermediate lever. and the master-` i andthe retarderfleverfhave La position/such i .-that,-althoughlthe retardenlever .is held, by

lthecontroller, away from the intermediate` j termediate i, lever and the retarder-lever is not in the nature ofa severe blow, by which# f the partsof --the retarder are -1 Suddenly inthe natureofa wiping action, suchv as to throw vthe parts into movementzgradually,

The-increased mechanical' advantage' `of the intermediate lever vover the-retarder-lever,

near the last part of the operative movei ay `,longer v'operative connectionbetween theft'V retarder and the; actuatingfmechanism *for the shorter exposures than would otherwise be v,the case, thus furtherfreducing their sudden and violent engagement ofthe lpartsland the preponderantelfect lof inertia inthe ref tardngaacteni. f

.Il claim:.-` ,l f .f

.1.; photographic shut-terhaving,in'com% bination, a retarder; actuating-mechanisms;

and *CODUGCIlS between said mechanism andthe retarder, foraactuating the latter,

constructed and arranged to give the acuat,--.j

v ing-mechanism aA mechanical advantage over, e fthe retarder.wliich increases' substantially toward/the Y 9J.v A photographic sliutterhaving, lin com-y last part yof theroperative move# bination` a retarder.; actuating-mechanism;

and connections betweenl said mechanism and e the retarder, for. actuating the latter, comprising g levers having effective arms whichr varyf in -suchsense as 'Jtoj give the l actuating-,mechanism va ymechanical `advaik 'A HA photographic shutter having, incomeL y bination, a retarder; controller to vary thel nected with the retarder; and an `ntermef` f'diate lever cooperating with the retarderf flever1 V,and Athe `masterglever; the retarder-l lever and the intermediatelever .eooperating,

with ,effective lever-arms which vary in suchr i y length of the operative ymovement of the reftarder; master-'leverga retarder-Jever conf` sense-Vas:l .to give .the intermediate; lever a;

Y mechanicaly advantage over the retarder-le;

ver whichl increases substantially toward thel last part i of the y'operative movement.

,o ANDREW ,'woLLENsAK. v. Y*

Copies'. ofY this patentimay..belobtaned for jive cents each,- addressing,thek deminisstonerefIa/tentsf'f 

